Help you? With what?
You choose one, you buy it, you put it on.
Do you need the help in choosing which one, buying it, or putting it on?
To help you choose one we would need to know a little bit more about your boat. Does it have a tower? Speakers? Are the speakers mounted on top of the tower, or hanging down from the top bar?
Are you willing to pay more for a bimini that you will really like, provides lots of shade, holds up well and looks nice, or do you need something cheap?
In general, my recommendations for a bimini are:
1) Head room: you will want to be able to stand in the boat under the bimini.
2) Fore & Aft coverage: For most of the day the sun isn't directly overhead. If the bimini doesn't extend a few feet forward and aft of the seats it won't provide adequate shade.
3)Mounts: If you have a tower, get a bimini that mounts to the tower, perferably with mounts that clamp to the tower rather than requiring you to drill holes. I strongly discourage any mounts to the windshield.
4) Obstructing the sides of the boat: Many bimini setups require the use of straps that run forward and back. The forward ones are generally not too bad but the straps that run back can be a real PITA. If the straps block your entrance from the side you will have to climb into the boat from the back.
My highest recommendation go to these guys: http://www.towerbiminis.com/
I have had their biminis on my last two boats and have loved them. I would recommend getting the stainless poles. They cost more but the bimini is a lot stronger. My previous boat had the stainless poles and I could chin myself on them! New boat has powder coated aluminum (matches the tower) which have held up fine for three years but I have to resist swinging from the bimini to jump into the driver's seat.