Wiki has a good list of Clickies here:
http://wiki.project1999.com/Clickies
As far as cheap and attainable clckies I say start with
http://wiki.project1999.com/Shrunken..._Skull_Earring .
This drops off a 32 Goblin in Warslik Woods. You could group it in yours 30s or maybe solo it in your 40s.
WW is an excellent zone for the 20s and 30s. So if you're feeling adventurous you might wanna go there for some grouping.
After that in price and availability is probably Deepwater. It's the Paladin only Kunark clicky Armor. The Chest/Legs will be unattainable to you because of cost. But the Boots (Resist Magic clicky) and Helm (HP Buff/heal) are cheap-ish and useful.
However, they can't be clicked until 45.
And of course the #1 clicky to get is JBoots. But they cost ~7kpp + 320pp for the full MQ. You could camp the AC but you'd probably need to be in your high 40s or low 50s to solo him.
See
http://wiki.project1999.com/Journeyman%27s_Boots for more information.
There are two ultra rare clickies that drop in LOIO (Lake of Ill Omen) which are handy. But if you're lucky enough to loot one it's probably smarter to sell it to buy better armor, jewelry, etc. List:
http://wiki.project1999.com/Bracer_of_the_Hidden
http://wiki.project1999.com/Goblin_Gazughi_Ring