The 1' IPS is what I build my frames with: no worries so far. I think it's as strong as the 1-1/4 IPS aluminum used by NRS. But it's really crucial to put dowels in the frame ends that go into the SpeedRail joints.
Footbar wise, for a raft frame you'll probably want something like this:
Two of the #5 Tees (with three setscrews) and two elbows. Also some safety tread stuff (get the gray rubbery type, not the black sandpaper type).
When you order fittings, it might be smart to get a couple extra tees and elbows, in case you want to change things around.
Anyhow, let me know your final call. I've got recent Hollaender prices on invoices. For current prices, I call.