I'd go see the machine first, before you even try to start to make a decision. Is it really a nice machine? How much backlash? etc?
I bought a bigger (2hp) CNC Series 1 Bp for about $2000, and am spending a bit over $1000 to update it to modern electronics, Geckos, PC, emc2, etc.
You're going to have a bit more money in that one, as you probably need to buy some big steppers and ball screws, not to mention making lots and lots of brackets to mount things.
The up side is that you'd have a decent mill available to make those parts....