Magnum w/Retracts
I spent some time looking into the retracts-issue earlier, and came to the conclusion that the ones available (and suitable) will not fit in the wing...
The smallest ones from Robart will fit, but they'll never be able to take the punishment that the Magnum will give them. You'll spend more time fixing the retracts than you'll spend flying...
One other issue is that i can hardly land the damn thing at idle, so i would'nt even dream about using it on tarmac with wheels... You would most likely have huge difficulties stopping it...
...and as to the weight of the Magnum: Add retracts, wheels, servos for retracts and rudder/nosewheel-steering, and you'll start to get close to the maximum weight on the small Robarts..
I gave up the idea, but i wish you good luck..