Regarding lamps you can use in the Tota light... you can use whatever is listed on the back of the light and a few others that are not listed but of the same length. It doesn't matter where they are purchased. There are a few websites that sell lamps, including this one:
BulbConnection.com - Lowel Replacement Lamps - Name Brand Bulbs for LESS!
Click on the Lowel light you want lamps for, and they are listed. Prices at specialized lamp/bulb sites are generally much lower than at camera stores. Prices for lamps at film expendale stores seem to be in the middle.

Regarding blue gel/filter, if you are talking about CTB, for changing the color temperature from warm to cool, it is used when ever a light is too warm and you want it cooler, either to match other lights (or daylight) or for a special effect (such as simulating night).

CTO, orange, is the equivalent to go from cool to warm.

Both of these type of gels/filters come in grades, such as 1/4, 1/2, and full.