I bought my axle from soutwestwheel.com. You can specify hub face length from 45-95" in 1" increments on whatever axle you want (2000lbs, 3500lbs). You specify whatever bolt pattern you want and they ship with the spring seats loose so you can mount them wherever you need. Which worked great for me since I converted an old seadoo trailer I picked up for $100 into a camping trailer and needed a 65" HF and springs mounted at 47" (i think, can't remember). All of the axles I was finding locally already had the spring seats mounted and to get an axle with hubs and loose spring seats was going to cost about $200. Got my axle with hubs, lug nuts, spring seats, and u-bolts for $144 shipped to my door, and it arrived like 2 days after I ordered it! I actually ordered my axle and then found wheels that would work before I purchased them. However, I built a frame out of angle iron and expanded metal and welded it to the trailer frame for my clam shell box to sit on so I was able to mock up everything to give proper tire clearance. You will also need to make sure the center bore hole on the wheels you will be using will be large enough for the hubs. Ended up using the old Jeep wheels (the 5-star if you are familiar with Jeep wheels) that have the Jeep engraved into it because I have a Jeep. You may call them and ask them about fitment, they are very helpful and could save you time in searching for wheels that would fit the hub if you don't already have your wheels.
Hope this helps and good luck with the build!
Oh yeah, based on my experience, whatever your budget and time frame are you should at least double both of them and tell your wife it is taking twice as long as expected but it is about half the cost you though it would be!
