is 80,000 Yen enough for 7 days in Tokyo?

Also, what is the best train pass to buy? is there an unlimited pass we can buy while there - we are only wanting to travel to main cities like Shinjuku , Harijuku and one day out to Fujikyu? :) YAY

I went to Tokyo last year with a budget roughly 10,000 yen/day (not including hotels which I paid for in advance). It was great. I had enough money to do all the things I wanted. I am a simple traveller though and don't care for 5 star restaurants. For getting around, I purchased subway passes from Narita Airport. I don't remember now what they were called but they were very reasonable, something like 1,000 yen for an all day pass. I just bought one for each day I stayed and never had trouble getting anywhere. I remember it didn't work on all of the lines, but there are often more than one line going to the main stations. Get the color coded subway map and keep it with you. That thing is invaluable.

I think it depends what you're going to do in those districts and is it 80,000 each or total for both? For two people that is probably low budget but if it's for each then it is probably medium budget.

This page has a ton of great info about getting around Tokyo. Most of the passes don't seem to be great value unless you're travelling excessively as fares are relatively cheap per journey.

http://www.japan-guide.com/e/e2017.html

I'm travelling to Japan in a couple of weeks and for the Tokyo portion of my stay I will be getting a SUICA card so I can travel in and around the Tokyo Metropolitan Area with minimum hassle.

If you're flying into Narita airport, look into the SUICA/NEX package, which gives a great discount on train travel from/to the airport as well as equipping you with a SUICA card.

Is that for 1 or 2 people, and does that include accommodation?

For 2 people including hotels, 80000 will be extremely low budget. For 1 person including hotels it will be low-med budget. Also, single tickets will probably end up cheaper than day passes.