I am preparing a detailed answer to your question. Watch this space...
Update. Most of this info is consolidated/recycled from earlier OGR posts which I found using the OGR Advanced Search tool, looking for Contains All of These Words: "Tortoise AIU" and Posted By my username: "stan2004". Or click on the following link which hopefully gets you the same result.
So here's my summary of the Tortoise issue using AIU SW(itch) ports; I'll address the block control issue using AIU ACC(essory) ports separately. I see you already have 12V DC wall-warts so I'm going to assume the issue of a DC power source does not need review.
As of today, the MTH website continues to suggest using an external DPDT latching/locking relay to control a Tortoise from an AIU SW port: http://www.protosound2.com/pdf/AIU_Tsw.pdf
The one-page PDF instruction sheet is also attached to this post in case it vanishes from the MTH website. In it, MTH suggests the NTE 50 relay which is quite spendy:
The suggested relay has so-called Quick-Connect terminals, sometimes called blade or Faston terminals which are convenient if you have them. Otherwise I suppose you can solder to the 10 terminals running the wires per the diagram. Or you can buy a mating socket which routes the 10 relay terminals to screw terminals. But now you're pushing $40 per Tortoise! And you have 25 Tortoises... YIKE$.
To give MTH the benefit of the doubt, I think they were just trying to illustrate the concept. You can use a much more economical DPDT latching relay that runs about $2 and is widely available - for example from DigiKey which is a US distributor popular amongst the OGR DIY'ers. You would have to solder wires to the 10 terminals using the MTH diagram.
And somewhere in-between, there are off-the-shelf DPDT latching relay modules with screw-terminals (so no soldering). For example, from Azatrax for just under $15 each:
So here there are 9 screw-terminals, as 2 of the 10 relay terminals are shared in the configuration suitable for driving a Tortoise from an AIU SW port. I didn't look closely but the relay that Azatrax uses on their assembled module may even be the $2 bare relay suggested above! In this post, I provided some ideas on what it involves to mount/wire the bare relays. In the last year or so, there has been a flurry of activity here with guys designing their own bare circuit boards for projects like this. This has come about because of "free" software to design the printed-wire boards and remarkably inexpensive board fabrication sources. Duplicating the Azatrax might be around $2 for the bare board in small quantity...but obviously someone would have the do the design.
And I'll throw in yet another idea explained in this OGR thread.
This uses a ~$10 latching relay module that has 6 relays. Using 2 relays per SW port, you can control 3 Tortoises. So only $3-4 per Tortoise...but the key is no-soldering required. The explanation (a.k.a. the fine-print ) can make one's head spin, but as discussed in the linked thread, another OGR member tried it and it works - including ability to use with the DCS "Route" function to set up all your Tortoises which I realize is a "must-have" requirement.
Finally, I see Joe ferreted out another arguably hare-brained alternative use essentially "makes" a latching relay out of non-latching relays. It's just that these relay modules from eBay have become so ridiculously inexpensive (with free shipping from Asia). Yes, lots of wiring, but then only $3 out-of-pocket and no-soldering! As discussed in the linked discussion, I'd say it's more food-for-thought than a practical solution.
So these should give you some ideas for the DPDT dual-coil latching relay part of your question.
Your other key requirement is ability to co-operate with a control panel - so either the AIU or control panel buttons can throw the Tortoises. Consider the following diagram recycled from one of the above linked threads.
So far what I described have been alternatives to what goes in the tiny box labeled "DPDT latching relay" in above diagram. If you want simultaneous ability to control the Tortoise with control panel pushbuttons, then wire in two momentary pushbuttons as shown. Or, as shown, you could also use momentary 3-position (center-off) spring-loaded toggle type switches which would then only require drilling one switch hole per Tortoise in your panel.
Hopefully this provides the Reader's Digest version of earlier threads. No doubt there are some details I failed to consolidate here so slog through the earlier threads... or feel free to ask for clarification!