I looked hard at flexible solar panels of many brands and didn't want to spend premium prices. I tried to strike a balance between quality and price, and found that Renogy had decently reviewed panels at a mid-price point, but most importantly they have a really good warranty - which the cheap panels do NOT. I bought their 160 watt panel and mounted it on my Bimini, and it performs well. Its not a miracle worker, but I've gotten 710 wh of power out of it in a really good day, and its now in its second season. If you go that route a couple of recommendations:
1. Buy directly from Renogy - not Amazon, etc. They have sales frequently (there's one on right now), you're getting fresh stock - not something from a year ago in a warehouse, and if there's a warranty issue you work with them directly.
2. I have noticed some white spots on my panel at the end of the first year. I talked with Renogy and sent them photos and they had me run a test on the panel whose results indicate they don't seem to have affected the output - yet. But they assured me it was covered under warranty if it became a problem.
3. If mounting on a Bimini consider having your canvas shop do a custom install for you. It will look much neater, and be much more secure that way. They do a lot of them, so its pretty routine.
I just assume with a flexible panel - even mounted on top of the Bimini out of the way - that I'll get 5 years out of it and probably have to replace a mid-priced panel. It was $299 on sale - and right now its 15% off. The warranty on the panel on their website is:
25-year power output warranty: 5 year/95% efficiency rate, 10 year/90% efficiency rate, 25-year/80% efficiency rate
5-year material and workmanship warranty
If they're willing to stand behind it, I was willing to take a chance on it. So far its worked out well. Their 100 watt panels might fit your space. One thing I found was that you're somewhat limited by the panels that will actually fit your useful space, so you may have to look around to find the best fit from a manufacturer.
Good luck.