I have bought a 1000 cells from mlsolar, and he's a good seller.
I personally like the 6x6 and have gotten 11 amps into the mttp grid tie from a string of these types when the sun is clouded a bit. Seem to pull 8A whenever good sun is about.
3x6 don't seem to have the same grunt, even though they are about the same area.
For sheer ease, I like the fred ones short tabbed.
I use 66 cells per panel. For short tabbed front and back, you just add about 1 inch of tabbing to the front, and your done.
For the 3x6 loose tabs, you need to retab each cell... bad....... but the fly leads are there already..... good but you do need to do twice as many cells for the same sort of power (I used 138 of 6x3) so you do easily twice as much work, for probably no more power.
Choice is yours.
Tabbing... this is code for slow laborious brainless work. It is the string of tinned copper on the front bus bars of the cell. It is not quick, unless you have a BIG iron that can hold the heat in the tip for a bit. A little iron is next to useless. You need to RUN the solder to avoid peaks and crests in the solder face, or they will crack the cell when the pressure comes on from the plastic via vacuum.... ie they stick up, and the cell does not bend.... on u tube videos on this, they don't mention this, as they were not going to vacuum press them.... just silicon them to a surface, so it was of no interest how flat they were.
Thats a good reason to have the factory tabbed ones done properly. Ive tabbed 1200 cells completely, and am still not great at it, as my iron was only a 60 watt pencil iron. If I had a rough and ready plumbers 60 watt iron, I think it would be a breeze comparatively, as the temp would hold better during the 6 inch runs...... the silicon saps it up very fast ( the heat).
So, by the time you buy buss wires, flux pens and solder and extra tabbing if required, probably a better faster result will be with these
:
http://www.ebay.com.au/itm/1000w-DIY-solar-cells-panel-kit-6x6-cells-wire-kit-/170797333359?pt=LH_DefaultDomain_0&hash=item27c4507b6f They supply all the stuff, and you can do 500 watts plus a day easy..... little cells are a pain if you doing lots of power.
............oztules
Edit... there is always a down side.... big cells are much more likely to break if your not very careful. If they break top to bottom, just use cellotape to stick them together to look nice. The power will not drop, same with cross wise.... diagonal can cause some losses if there is no white silver paint joining up the broken piece. 3x6 are a bit sturdier to use. So that may come into your calculations as well. I find if you use the cardboard to move, flip, shift the cells and never actually handle them with your fingers, this seems to stop the breakage. Once your fingers grab them, chances are a breakage will occur, as we are not aware of the air pressure against them as we move them about. Move a 6x6 quickly only holding the corner between your fingers, and it will break. Use the cardboard like a spatula, and you will probably never break one.... maybe because it is awkward enough to keep you thinking.
