A table saw definitely has the best results. But I would use one of those cheap table saws. They are not very accurate and generally not even very safe, being without kickback protection usually. I consider purchasing tools to be an investment, and I don't see a sense in buying 2nd rate tools that I'll just end up replacing down the road anyways. If you wanted to invest in a table saw, there is one particular portable model by Bosche that is superior to everything else out there; it is a superb contractor grade portable saw. It has a great, superbly accurate fence(unlike everything else in this category), superb build quality, fairly powerful motor and it folds up and has wheels for moving/storage. It does cost $500-$750, depending on where you get it and what options you choose(there is a digital read out fence indicator option and extension rails options). If you get a high quality miter extension, it can be used as a great miter saw too, but never count on the miter extensions included with these saws as being useful - they are usually always junk. A high grade 3rd party miter extension tool is around $100-$130 from amazon.com.
You can also use a hand held circular saw to make accurate cuts, provided you get a high grade one with a stiff/strong cast base with stiff/strong pivot joint. You would make a special jig using a guide and extra wood on saw horses, which I can describe in detail if interested. It won't be as easy to use as a table saw, and it takes even more space to store, but it's a cheaper way to do it if needed as compared to a good table saw. A high grade circular saw suitable for this application is about $150-$250, depending on the specific one chosen.
-Chris