RE: Looking for a new RC car on a budget.
The Jato is a great choice. The only hop ups I would recommend are RPM arms. The HPI Firestorm is also a great choice. Both trucks can be modified like crazy but don't really need to be.
I would also reconsider the monster truck thing. My Savage X 4.6 is a blast, really needs nothing (mines is completely stock), and his about 45mph with no problem. The Savage can also take one hell of a beating.
Also look at the AE RC10GT2. A little lower on the price scale, has great parts availability, and is also a blast.