what to do in Kyoto and Kyoasan

Basically I am going to book my airplane ticket today

I am going to those places on 2nd Oct and then leaving to go to Tokyo on 10th Oct

I have 8 days to do things there at maximum. I wanted to visit Kyoto and Mount Koya for cultral and temples.

Now I was going to stay at M.K for about 1 day or maybe 2 to stay at a temple and the rest at Kyoto and go sigh seeing, shopping and what not.

Does that sound ok or should I cut Kyoto & MK trip down

It depends on your preferred pace of travel. If you like a medium to slow pace, then I think 8 days for Koyasan and Kyoto are perfect. I recommend to stay one or two nights on Koyasan and the rest in Kyoto.

About Kyoto:
http://www.japan-guide.com/e/e2158.html

About Koyasan:
http://www.japan-guide.com/e/e4900.html

Kyoto is a wonderful place to spend a week. I highly recommend a day and night in Koya-san. Keep in mind it takes about a half day to get there from Kyoto. Okunoin Cemetery is overwhelming. Stay overnight in a Buddhist temple. In Kyoto, the must sees include: Kiyomizodera, Fushima Inari Shrine (innumerable torii gates!), Sanjusangendo (1000 Buddhas), Kinkakuji (gold pavillion), Ryoanji (stone garden), Heian Shrine, Ginkakuji. Register online well in advance (weeks or even months) to see Katsura Villa and/or the Imperial Palace. About a half hour from Kyoto is Arishiyama -incredible traditional spectacle of cormorant fishing (in the evening, but go in the afternoon to Tenryuji Temple and/or Iwatayama Monkey Park first). I also recommend at least a day or two in Nara (about an hour from Kyoto). Another long (doable if you take the shinkansen) but very worthwhile day trip from Kyoto is Hiroshima (peace museum) and Miyajima (torii gate in water). Himeji Castle and Osaka are other possible day trips from Kyoto. Have fun!