Totally agree build your own! Initially I purchased a couple of sets of JAK Rollers. Tried these using MTH RealTrax since the rail profile had a wide flat top. I quickly found that this was not stable enough to run my Premier Pennsy S2 and UP Big Boy at near flank speed. So I designed and built these. NO problem at full flank speed of 120 SMPH. Also have meters but normally use my extra Z-4000. The longer one includes a second track to test operating functions on rolling stock.
On the initial long one can run any and all steam engines including C&O M1, N&W "Jawn Henry"and AA E=units also Pennsy AA Centipedes.
Also built a smaller test stand.
Also fitted them to a carrying case so can take them to shows to run anything I have for sale and test run engines for others.
Ron