best sea kayak rack

Any suggestions for a rack to hold three or more sea kayaks (@17 ft) in my basement?

The best one is designed for your needs. Who could know? Do you access them from the side? From one end? Storage overhead? Lots of options, the best is probably DIY.

I access from the side. I realize these racks are fairly expensive. I’m thinking about a cheaper option: Suspenz Universal Portable Boat Stands. Thoughts?

We finally bought a rack, a Suspenz freestanding floor rack with one Deluxe (folding) J ram and one standard J arm.

The rack is well made, sturdy, stable, and simple. Suspenz makes everything modular, so you can easily set up a 3-kayak system. If you need easy portability, you can even get caster wheels. I highly recommend Suspenz.

The rack is L shaped. The uprights are 4x4. The bottom bar is 2x4 and can hold as many boats as you want to size it for.
The upper 4 arms are made from exterior 3/4" plywood doubled and cut to the rough profile of the boats with nylon strap across the opening to support them.
I’ll send you more detailed photos if you want.

I built one for our two sea kayaks and our two paddle boards using 2" schedule 40 PVC pipe and fittings. It was fun to build and I didn’t glue the pipe to the fittings, but instead used one screw for each connection. In that way it can be taken apart or revised to hold more boats.
I glued el cheapo heavy duty rug mats to the cross supports for easier sliding the boats on from the end.
In our boat barn We access from the side and I simply used heavy duty shelf brackets screwed to the studs. I added wooden extensions to each bracket to make them wide enough and covered each with gray pipe insulation. I have them four high and each is holding a long canoe or our sea kayaks.
I also have center columns which I added cross arms which old canoes and kayaks on each side.

Get creative - Where there is a will, there is a way !