The first question is have you ever completed a full rebuild? By that I mean measuring everything (using a bore gauge, micrometers, runout gauges, or having a machine shop do it). If not then rebuilding an engine may not be something you want to take on especially with no prior experience or tools. Having a shop like KWS build your engine is your best bet. With that said you should plan on having $5k to spare in the event that you cannot just drop in new rings and need nikasil or head work etc. Mileage and abuse will obviously make the tolerances looser and your rebuild will be more costly. If your not doing a complete refresh then internal mods are a bit pointless (like putting a turbo on a engine with 200k miles lol). If you want a fresh motor then that's fairly straight forward minus repairs etc. If you want more power then the above post are the best route forward (get a 1000).