BTW as much as I despise that online auction site their prices on the alarm stuff are tough to beat Here's the honeywell site http://www.security.honeywell.com/hsc/products/control/bu/ad/14958.html They bought out Ademco so all the Ademco stuff floating around works too.
ok how about a driveway sensor for a screaming alarm and flashing lights. Also a traditional alarm with glass break sensors, motion sensors, lights and alarms. It can all be made wireless and it's very good. Honeywell Vista 20P. You can do all the programming yourself. You can even program it while at home and then just install it at the site.
Im not sure how long the batteries last, even when hooked up to a car battery. I think the night illumination source might be visible (glowing red) in the dark. Some also flash which would bad. Regardless I think visible cameras even dummies might be alternative. Do you have electricity there?
Here's an excellent optics forum http://www.opticstalk.com/ which is operated by these guys http://swfa.com/ I have one of these http://swfa.com/Simmons-6-18x40-Pro-Target-Rifle-Scope-P48588.aspx on a .22 and I am pleased with it for an inexpensive scope