I don't do hand sewing either, so can't help you with hand sewing needles.
As for your rotary cutter and blades, I use my 40% off coupon at Jo Ann's or wait for them to go on sale. The most common size is 45 mm, but there is the smaller 28 mm and the larger 60 mm. Look on Jo Ann's online website and some other online places like ConnectingThreads.com or NancysNotions.com. You can probably Google it too.
Good luck!