I'll add a few thoughts myself as someone who's come to spearing from fishing.
For UK shore spinning I think you are best off with braid. There are many reasons for this.
1) Instant hook up, the lack of stretch means you are immediately in touch with the fish and can set the hook straight away.
2) Stronger. I use 40lbs braid when plugging. Its fine diameter allows plenty of casting distance but it gives you the added bonus of being able to pull the lure out of most weed beds. It is more expensive, yes, but it pays for itself in lures you would otherwise of lost.
3) Its limper. Braid is not as stiff as mono so it sits on the reel better and doesn't spring off the spool causing tangles.
4) Touch. You can feel whats going on with braid due to the lack of stretch. This means you can feel when the lure is touching the bottom or weed and stop the retrieve, allowing a floating lure to rise above the obstruction.
5) No leader, you don't need a leader to cast as the mainline is plenty strong enough.
You will need a decent reel though, as you say, a 6000 size is far too big and unweildy. For braid a 2-3000 is plenty. MAKE SURE you get something that had a good line lay and an oversized line roller, preferably with some kind of twist busting system. The arch enemy of the plugger is line twist. You are retrieving so much if you have a reel that twists your line every other cast will end up in a nasty tangle. Also, for the same reason, do not over fill the spool, leave the line a mm or two below the lip, this will cut down the tangles. Also put a small swivel on the lure link to remove as much as possible.
Braid is not difficult to knot, I've always used a 4 or 5 turn grinner or uni knot, which are easy to tie and never had any problems. As miles says its the last few metres which get the abuse so cut a bit off every couple of trips.
This is all specific to lure fishing and doesn't neccessarily apply to anything else, Miles has it right warning how complicated it gets! But its all good fun. You don't need complicated casting styles for lure fishing, they'll make no difference to distance, but a sound technique would be useful.
And finally just a little bit of boasting, 130m eh Miles, nicely done in one session, keep practising and you might catch me.....224m
