I admire your low-budget ingenuity - and the results you've gotten so far. Also understand about the boss being a tightwad. I've done a lot of eBay ad pictures with a similar setup - and typically draw nearly twice the price of competitors, simply by having better pictures.

Given the stated budget limitations, I would go for -

* The Circular Polarizer - limited effect on metallic glare, but does wonders with glass reflections.

* At least Two more of those Halogen Lights - you need a bit more light, from what I see. The additional units would also allow you to light from more angles, for better manipulation or elimination of shadows, as desired.

* A few White Bedsheets - which you can use in rigging a Light Tent. Can also hang one up to block a reflection, if that's ever a problem. And they can make a nicely textured alternative to your white paper base, when desirable.

* And.....A Fire Extinguisher - just in case anything gets a bit too close to those hot lights! Throw in a Smoke Detector while you're at it - it can detect a smoldering sheet before you can smell it, in a lot of cases.

I'd go with that, and hold off on repainting the place for a while. Re-do the catalog and double sales first, developing your skills along the way and generally impressing the boss - THEN press for a 'real studio' budget, to soar to even greater heights.