Small and micro (5mm and 4mm nominal inside diameter) arrows are the going trend, but my advice is to keep it simple and stick with a standard diameter (6.5mm/.245" ID) shaft. Cost and complexity increase and the insert can become a significant weak point as you go smaller, and the supposed benefits of a smaller arrow are marginal.
Choose a standard diameter shaft of moderate gpi, cut it about an inch shorter than your draw length, and use a combination of insert weight and point/head weight to get total arrow weight around 7 grains per pound of draw weight. That will give you a strong arrow with a good balance of weight and speed at a reasonable price.
Black Eagle Outlaw, Easton 6.5mm, Gold Tip Hunter (or its Bass Pro-branded Blackout clone), and Victory VForce (or the Scheels Vendetta clone) would all fit the bill. Any of those in 340-350 spine cut around 28" with 150 gr total on the front and about 30 gr on the back would hit your target TAW and should have adequate spine at 60-65#.