how much are you wanting to spend? Are you renting this slip? If so they likely have restrictions on what you can attach to their structure. You will be limited to self contained (more expensive) lift. How deep is the water? If it is shallow, you can find a used shorestation or similar cable lift for a couple grand. 3-4. Or if you want the caddy of lifts, get a sunstream hydraulic. Floating lifts are needed for deeper water and run more. check
www.tigerboatdocks.com for used lift inventory. Call the number and ask what the current inventory is or if someone is selling - my dad sells a lot on consignment for people.