Thanks guys.
I have had a look around here in the Trains section, it is where I saw the BR Class 37, I think it's made by a user called Bricktrix? People tend to post just pictures of the final result, rather than instructions and part lists though.
I found out about how to do a few 9v mods and still use PF functions, sorry I answered my own question on that.
I also found out about BlueBrick, and made a couple of layouts that would fit in a 6 feet by 6 feet space last night, one was 6 foot by 3 foot and double circle plus a couple internal sidings, one to place the 60052 set's crane at, based on someone's I have seen on here, the other was the same but with a "train yard" added on to it that feeds into the main section of tracks (I'm not very inventive).
Thing is I just remeasured the space I would put the tracks down on (the middle of the floor of the biggest of the rooms in the house I live in) and the available space in the middle is actually only 60 inches by 60 inches (with a few inches either side to walk round), so 5 feet x5 feet (roughly 1.5m square)...
...that brings this idea to a head I think - I am actually considering giving up on having a Lego train set before I've even started. I can't feasibly put a decent layout in a 5 feet square area, I can just about fit into that area the track layout from 60052!! Plus I costed up the extra track I'd need even for the 6 feet by 3 feet layout I made in BlueBrick and even though I would have the track from 60052 I would still need nearly £50 (or more) worth of extra track, the most expensive being straight bits which seem like gold dust!!!
The cost of parts just seems horrendous, particularly track sections given the amount needed. Even looking on places like Bricklink (it's fine saying a straight piece of track is £0.99, but if you need 27 of them that soon adds up). And even before I've considered what parts I'll need to "accurise" a loco or build an "accurate" loco!!
I have my eye on a 60052 set at a low cost, for the moment, it's on an auction site though which means the price will probably sky-rocket to in excess of £100 in the final seconds, but I'm just not convinced that a Lego train set with a decent/fun layout is within my means. I don't think I have the room and I don't think I have the finances. I can understand why my parents never bought me a Lego train set as a child.
EDIT - However having said that I've just had a play around in BlueBrick again and come up with a 1.5m square layout. Haven't costed it up yet though (for the extra parts that don't come with 60052) and I don't know if the left most "siding" would even work, at best I think I can put a loco down it then back up again on the furthest left spur. The crane from 60052 would be placed on the siding furthest right. I've had to use several of those flexi-track bits and I'm not even sure the track entirely fits together properly in those places. I'm also thinking of putting another single crossover on one of the sides because I can't see a way the train would "get out" of the inner loop without reversing.
Here it is -