The buggys are super durable, but lack ground clearance and the little tires only can do so much when off roading/bashing. But with a Truggy you'd have the simplistic layout of the buggy and be able to incorperate much larger MT sized tires. The diffs on any truggy are going to be BL ready with out any mods unlike some MT's.
If you decide on a MT a LST2 or even a Losi Muggy is a fine candidate. Rollers can easily be scored cheap via Ebay as well as any roller Truggy.
I couldn't pick between a MT or a Truggy,they each have their own apeal. Thats why I have 2 MT's and 2 Truggys and 2 Revos