You my friend have a bit of research in front of you.. But I will get you started.. likely the ticking sound you are hearing is your HLA's.. pretty common in a engine with that high of mileage. HLA = Hydraulic Lash Adjuster or as more commonly called, Lifters. Now.. I am not positive the SOHC engine has HLA's to be honest.. thats where the research comes in

Use the search button up top and start by searching for something like "SOHC HLA's" Or some such.. or maybe a bright fellow by the name of 93SOHC can shed a more positive light on this. As for the rebuild.. most folks will tell you that engine is not really worth the expense.. and.. well.. they are a dime a dozen and you can buy a complete replacement engine for $400 or less. Which is a LOT less cash than you will spend on a head rebuild for your current engine. But probably the first thing you should do is a compression test. This is a very easy test to perform and it will give you an idea of what condition your valves are in. You can buy a compression tester anyplace you can get tools or auto parts. Here is how you do it...
1) Unplug the wiring harness from your distributor
2) Disconnect your spark plug wires - make note of where each one goes
3) Remove all 4 spark plugs
4) Screw in the compression tester to #1 cylinder
5) Have a friend crank the engine over until the needle on the tester no longer moves up.
6) Repeat steps 4&5 for the remaining 3 cylinders. Making sure to record your results.
7) Reinstall your spark plugs, attach your plug wires in the correct firing order and plug the wiring harness back into your distributor.
Now.. what you want to see are relatively even numbers.. a 10 psi difference between cylinder results isnt too bad for a engine of your mileage. However.. if you find the varience to be more than that.. or if one or more cylinders reads extremely low.. it can indicate that your valves are not sealing properly. For a engine of your mileage.. assuming regular oil changes and decent upkeep.. I would expect to find at least 135 Psi per cylinder. Higher than this is great especially if all of your cylinders are higher. Now if you find something like.. 150, 145, 40, 155 across your cylinders.. # 3 cylinder (reading from left to right) has some serious issues. Likely a burned valve.
If you find the results of your compression test to be unsatisfactory.. I would recommend replacing the whole engine rather than dinking with a head rebuild. Especially if you can do the engine swap yourself. You could also take the opportunity to upgrade to a more powerful engine if you wish. This again is where the search function will come in handy for you

Hope this helps.
Tunes67