Size, weight, and gear length all but require the use of metal pneumatic retracts over the plastic mechanical ones they recommend. I contacted Robart, found out what they used on their TT Rare Bear, and ordered the same stuff for myself: 551RS 85-degree robostrut ready retracts, 661L/661R Robostruts, and 188VRX Deluxe Air Control Kit.

As for tank position I will be using a YS engine which utilizes crankcase pressure to pressurize the tank. Fuel tank will be over the CG and position will not be a problem (flooding or otherwise).