We used small paper pots for starters last year for practically all our seeds. Very easy to make and do the job fine. However, I would recommend pealing them off when you transplant, or making sure you use minimal paper. Some of our paper hadn't composted very well and in some cases restricted root growth. Don't let that put you off though, but do bare it in mind.
If you go with horse manure be careful it isn't too strong for the seed varieties you'll be using.
Toilet roles come in very handy for leeks.