Welcome new guy here. For a 21ft boat, you are best off with a tiller. Wheels are nice and my 27 has a wheel, but for smaller boats, tillers are best suited. The tiller saves cockpit space and you will get better turn control over a wheel. With a tiller you can swing it just about 180°, however a wheel is limited by the quadrant and cables.
I am sure other will be by shortly to either agree with me or tell me I really should give up sailing. LOL
Anyway, welcome to SBO.
Unless sailing a Pogo, Beneteau 30.1, First 27, First 24, First 25.5, First 260...... etc....Under 25 ft or racing tiller gives better feel, over 28 ft or cruiseing wheel gives more cockpit room and is worth added cost and maintenance.