Just in case you didn't notice, anchors and rodes are very sensitive subjects on
forums: opinions differ widely.
Q1: I suppose that you don't have a
windlass, so I suggest that you get a 10 to 12kg (22 to 26lbs) good-quality, sea-proven
anchor (Delta, Spade,
Rocna, Manson Supreme...).
Q2: There are two schools of thought: all chain (costly, heavy, not much elasticity but resists well to chafing) and rope+chain (cheaper, lighter, more elasticity for shock absorption but sensitive to chafe).
I would suggest at least two
boat lengths of 8mm chain plus 50m of 14mm
rope permanently attached (splice or knot) to the chain, plus another 100m of rope stowed elsewhere. With this tackle, you should be able to anchor in 20m of
water, in normal (not gale or storm) conditions.
It would be prudent to have a second complete
anchoring tackle, just in case... I also suggest that you do some reading and thinking, to make your own mind on the subject.
Alain