If you have a drop saw or compound mitre saw that will handle the material size, then no problem. Get an 80T or 100T blade from your supplier to suit, make sure you tell them it is for cutting aluminium. Also get some cutting / lube compound, comes in a wax stick like a giant candle.
My blade is an Irwin that cost me $90AUD and cuts 8020 like butter in my 8" drop saw. Make SURE you clamp the work well and use a smooth clean cut, not stopping or backing off halfway. The swarf is like fine snow so I put a stocking over the motor housing to keep it out, wear eye and breathing protections as well, if you think sawdust is bad for your lungs try fine aluminium.
I am also starting a new 8020 build, see my thread at http://www.cnczone.com/forums/t-slot..._build_oz.html (Proposed T-Slot 8020 Build in Oz)