If you've got the money, then buy the best. But for working on a 40, I think it might be overkill. I have a few flukes, but most of the time they stay in the drawer and I grab the free HF multi-meters. 99% of the time you're either measuring continuity or voltage. Neither of those really require a lot of precision, it usually a yes or no answer. Also doesn't hurt as much when you forget to switch the leads from amps to volts and blow the fuse. The fluke fuses cost more than a cheap multi-meter.
For torque wrenches I am probably one of the few people who still likes the beam style. Simple, durable, and no batteries or springs to wear out. Again, can't think of anything on the 40 requires high precision, so the beam style is it's durable enough that you don't have to worry about damaging it or calibrating it. I have 2 ft-lbs torque wrenches, a 1/2 drive good for 250 ft-lbs (for head bolts and axle nuts), one for mid level readings up to 100 ft-lbs (for most everything else). Then a 1/4 drive in-lbs for stuff like oil pans and timing cover. If you were to only get 1, a 3/8 drive 0-100 ft-lbs would cover most of your needs