A number of "noob" questions

[symptom]

Hello! I am pretty much new to the modding scene and had a number of questions regarding my current PS2 situation. I did read the UIS and although it did answer some of my questions and (moreso) motivate me to mod my PS2, I am still uncertain as to what I should do in my current situation.

My V4 which has survived for quite a few years is finally giving me the disc read errors with silver PS2 games and DVDs. I tried cleaning the lens and adjusting the voltage slightly but with no luck -- I'm still getting the disc read errors and clicking sounds while trying to read the disc (not sure if this started before or after I decided to poke around inside the system.) I've decided to give up on these "temporary fixes" I've read about because I don't want to spend money modding a PS2 that is gonna crap out on me soon.

So anyway, I want to be able to play backups of my PS2 games and at this point don't feel confident installing a modchip myself. Should I try to find a place that will fix my V4 and install the chip? Or should I buy a premodded system? If so, should I avoid getting a V12 and try to get an earlier version? Which of the earlier versions should I get? Which are still available, and where should I look? I'm trying to spend as little money as possible as I don't have much.

Any advice is appreciated

EDIT: Sorry, apparently I have a V3, not a V4.