Small Loft framing questions

[R6 Racer]

I am going to build a loft above the stairs that lead to the basement from my garage. (pics included) I want this loft to carry some fairly heavy weight. I will have my 60 gallon air compressor (250lbs), A sandblast cabinet (300lbs +)& either a motorcycle (400lbs) or a snowblower (less than 400) & me (210lbs). So I will want it to be able to handle 2000lbs at least.
Sides a & b will be attached to studded walls (16" on center) that are currently drywalled. Side d will be supported by a 2x4 studded support wall. The top deck will be 3/4" plywood.

Questions
1) Which way should I run the floor joists... pic1 (loft 1) or pic 2 (loft 2) & why?
2) What are your ideas for attaching sides a & b to the existing studded walls?

 

[R6 Racer]

No suggestions?
At all?

 

[OneTon]

Loft 1. Shorter joists = more load bearing capacity.

 

[ArchInt]

I would attach it as shown in loft 1. That way the half the load is attached to the wall & half is sitting on the 2x4 wall. I would use 2x6 joist at 16" on center with joist hangers for the framing. And on side a, use lag bolts and make sure I hit every stud in the existing wall. The only building code issue I would look at is to make sure there is 6'8" clear from the edge of stair nosing to the bottom of the ceiling/loft.

 

[folgers]

Loft 1. I'm not a framer but I think I'd cut the wallboard off side b and use lags into the studs. I don't think it would be necessary to attach side a to the wall.

 

[blue dog]

Shorter span = stronger
attach a ledger to the walls A AND B, say a 2x6 or 8", nail off to each existing stud. 2x6 3 16d per, 2x8 4 16d per. You can all so add 2x legs under the ledger's.

 

[kenfath]

Loft 1 = Shorter is stronger.
Agree with all the other responses. Use 2x8" lumber, remove the drywall so your 2x8s are in direct contact with the studs. Secure the ledger boards using three 5" LedgerLok or some other fastener engineered for this application, to each stud. (Common lags and nails shouldn't be used -- IMO.) Use joist hangers.