I am also in a diesel program at my local tech school, and i have completed the auto program. i have been taking advantage of the snap-on discount as much as i can. My Rep does not have a problem with ordering what i want, i will also say email your rep with a list of tools that you want to see if you can get them at discount prices, not everything available through the program is online.
I would also recommend staying away from the sets... the two you have listed would be nice because they are complete, but for the money you are better off getting just the individual socket, wrench and screwdriver sets... go with channellock for pliers.
As far as a box, its up to you, you have a chance to get a snap-on box at half price, so why not. I have the kra2106 and kra2104 top/bottom... at the time it was the best price/size efficient buy, i got the combo for $1560 where most kids went with the kra2411 for $2100... I wish i would have just waited and bought a different box though. I would have bought the US General 56" box for $800. or the 40" set for $1100 (top, bottom and side lockers)
This fall I plan on buying the krsc31 shop cart. at $450 its a great deal. My box is full so this is the cheapest way of obtaining extra room and have matching snap-on (side locker=$1500 end locker=$750 end cab=$1125 drawer section=$1050)
From what I have purchased, I recommend:
impact sockets - the last sets you will ever buy, so it is definitely worth the money
impact swivel sockets - I use them all the time, you will find out that you will not always be able to get in with a standard socket. having swivel sockets is just that much nicer
dual 80 ratchets - at half price you dont want to pass this opportunity, its not the fact that they have a shorter ratchet arch, its the comfort, they are so smooth!
torx and hex bits - nice complete sets and they wont twist or break like cman or gearwrench, very dependable.
hammers - very comfortable and hard hitting, I bought the HBBD1632GX set, my rep suggested it, they are GREEN
I have the craftsman pro combo wrenches, made in usa, they are just about as good as the flank drives and i got the 26pc set for $150 last summer. now the craftsman pro wrenches are made in china, so i dont know about the quality.
As far as air tools. Ingersoll Rand has a student program. they have a set that includes the 2135timax and 1207max d3 ratchet for $299!! awesome deal!
good luck with your decisions!