I disagree with Bubbles (but everyone has their own opinion). I'd say try to build 200 wis as soon as you can.
+6 wis rings, the Platinum Ruby Veil, Bloodstained tunic (cheap, or free if you go to Unrest and one drops), those quested golden cleric bracers (Bracers of the Reverent...do it twice as they aren't lore).
In essence, look at this page for a guideline:
http://wiki.project1999.org/Cleric#Pre-Planar
Sure, Jboots are nice and they'll probably save you a few deaths but they aren't a necessity.
If you're looking to solo or want to be the best cleric you can be, you need a decent mana pool - aim for 200 wis or as close as you can get it as early as possible. After that, think more towards secondary stats.