Dave, I fish that beat on the Ythan now and again and you wont really need any fancy lines. The 9ft rod is a little restricting, there is a lot of weeds at the edge of the bank which extend out into the river, but you will manage to fish many of the pools. You will be restricted to overhead casting with that outfit, as you cant wade and the weeds at the rivers edge will catch your loop if you try to speycast with the shorter rod. This again is no real problem, you dont need to cast very far. For that rod I would buy a standard weight forward line, it does not have to be anything special, a mill end will do if you are operating to a budget. Cut the first couple of foot off the front of the line and whip a loop on the tip. This will remove the level piece of line at the tip and a little of the front taper and will make it easier the turn over polyleaders which you loop to the tip. A range of polyleaders or versi-tips will allow you to adjust the depth you are fishing at, also have flies of different weights from doubles to copper tubes which will further enable you to fine tune the depth you are fishing. With this you should be able to fish the beat in a low or medium water, but you will be a bit undergunned in high water, a double hander and sinking line is more suitable for this. For books, the Crawford Little one recommended by Hamish is very good, the Falkus one is quite sound with the advise, if a little dated nowadays. Other ones I would recommend are the books by Alexander Baird Keichy, they are a bit more up to date.