Hello from the Catskills of NY

Hello everyone,
This is my first post so I'll give you a little background:
I'm a retired electronic engineer, I still do some writing and magazine articles but I'm winding most of that down now as I want to devote more time to my solar projects.

At this point I have a 6.4Kw intertie from a grant through my rural electric coop that I installed last August. Before that I installed an off grid system with 8 Solarworld panels, two Outback VFX4836 inverters and an MX60 mppt.

I just purchased 12 Sharp "B" grade 240W panels on Ebay and am in the process of building tracking inverters for them and the 8 previous SW panels which are now in wood racks.

I'm MIG welding mild steel CRS steel tubes (or 6061 tubes depending on price) for the tracking frame but I haven't settled on linear actuators as of yet.
For the tracking electronics I'm going to program microcontrollers (I use Atmel's 8 bit uC's) with a twist. Instead of using LED's or CDS cells I'm going to program the controllers to follow the sun using a time algorithm that I will be able to control from my house, especially when I need to protect the panels in high wind or storms.

I was wondering if anyone has found a good linear actuator for a reasonable price? I haven't finalized the frame layout completely yet but I'm thinking about 18" of travel forthe actuators. I'll be making 5 structures with four panels on a structure using 4" sked 80 pipe in 18 to 24" sonotubes.

Rob