the stock 88 generation 302cu.in. was rated at 225hp, and thats a measurement at the crank, so with the modifications he has done getting the car to about 240 rwhp, which is real hp delivered to the wheels, measured by the dyno, is perhaps about right. the taller 3.73 gears in the rear end do not add power but of course they make the car quicker from the get go.
so to answer your question...is this a fast mustang, no.
if you are looking for a hobby and a project car and can do some of/most of your own wrenching and tuning depending on overall condition - then this foxbody might be ok to further enhance....but from the way your question is worded and the fact this is your 1st mustang, ownership of an old/highly modified profile might be problematic..
-holley carb does require specific tuning knowledge
-the engine he has swapped in seems to be same generation - based on the stats- and price seems high - cannot understand why the swap would not have entailed a later, more powerful shortblock. further enhancement to the existing engine he is running will certainly be expensive.
recommend - unless you want a foxbody as a project car - that you move into a later profile, with EFI....for $2000 -3000 more you will get the later profile, far better overall mustang, that will require far less maintenance, far less downtime, and be much better overall driving experience...even if you have to wait to get the extra $ together this will payoff in the long run.
here are a few canadian examples of what i am speaking of, since you are dealing on a C$ car.
here are serious foxbodies, that you can compare to the edition you are considering
good luck 2004 cobra