If you have the drive, all power to you to make your team better!
Keep in mind that bumper rules are a thing, so sticking your wheels out the front will only work if you have a bumper support ahead of that (maybe higher than the wheels?).
Versachassis stuff can only drop you 1/8", which is not enough for pneumatics most likely. Many teams had luck with colsons this year or a combinations of colsons and pneumatics; maybe 6" colsons in the center, dropped, and 6" pneumatics on the outside? That could solve your problem.
Versachassis is expensive once you total up bearing blocks, gearboxes, etc. KOP chassis with 6 8" pneumatic wheels is my suggestion purely from a cost standpoint. Custom will run you a bit more, and versachassis the most, mainly because of the gearbox setup. Unless you want to mill your own mounting holes for the gearbox you are practically forced to use the $300 3-cim ballshifter, so although the build quality will be really good you will be spending some money.
That being said, while working with versachassis I may have missed something major on gearbox integration. The advertisements say "any gearbox" so there might be a method of mounting that I've missed.
If you CAD everything, you can solve some of your beaching issues and stuff there. Just draw your drivetrain and the moat, and set it up in different positions. Just a simple 2D sketch side view is enough.