TBH the OP sounds like Carlton Banks...
But on a serious note I know what you are aiming at and have a couple of friends that wear this sort of thing, however it's just not me.
Jumpers: Spawn of the devil, in fact most things with sleeves are. Closest I get is a NF TKA 100 black/grey fleece that I wear with the sleeves rolled up if it's colder or otherwise sleeveless rugby shirts (mostly an All Blacks one due to it being very plain) because they are warm yet nice and mobile (not cotton ones but nylon/proper rugby shirts).
Shirts: I agree with Next, an excellent array of Shirts and usually where i get mine from due to a nice selection of slim fitting ones. Shirts should not be white (with the very rare exception) because it looks like you're a schoolboy and plain ones should be avoided, nice smart/colourfulish striped are good in my book. My favourite colours are purple/red/blue/mixed at the moment, faded/pale/pastel colours always looks like they are for 60 somethings.
Suit: M&S, although I only have one at the moment.
Trousers: I wear Jeans almost exclusively, normally from Next, sometimes from Topman and very occasionally from River Island, just plain, slightly faded ones, slightly on the baggy side normally (I'm a snug 32" waist so normally go for 34" jeans because they are less restrictive).
T-Shirts: Normally an Outdoor/sporty brand so my wardrobe is full of Animal/Fox etc. tees. Anything with big plain labels stuck on the front are out and I steer clear of the surf brands too (Yeah I know Animal could fall into a surf brand and it has a big brand label plastered all over the front of their tees but they are less surf, more outdoors/extreme sports and the labels are always well disguised as pieces of "art" rather than just a massive "BENCH"). Plain Tees are rather boring tbh and anything with a small brand label on is definately avoided.
Shoes: A pair of black slip on smart leather shoes for formal occasions and a pair of Salomon trainers for general every day wear, comfy, reasonably smart and ready for all occasions.
Jacket: Mountain Hardware softshell in an understated colour (black/dark greys). Alternatives would be the standard North Face softshell which is slightly cleaper and pretty good (warm as well if you get the thicker summit series), these do seem to be a bit common for my liking though. Still nice. If you have some money to blow then Peak Performance and arcteryx do some very nice softshells too.
Thing is I know I do look a bit scruffy a lot of the time but I am comfortable. I do think I could do with being a bit smarter on a lot of occasions (such as going out on a night out, I have very little between the casual and very smart) but most of the fashion in that sort of area looks terrible and TBH I'm very picky on what sort of clothing I like, normally only buying a couple of Jeans, a shirt and 3-4 tees a year because I am so particular.
My other wardrobe on the other hand contains much more variety...
Rab/North Face fleeces
Helly Hansen base layers
Schoffel Jacket (alongside another goretex)
NF Trousers
A variety of shoes and boots
Various pairs of gloves and socks...