DV Info Net - New to AVCHD

Recently purchased the Canon HF100 for home video. Need to get a new computer...so old an upgrade is not an option. I do not have software to edit the AVCHD but have been following threads in this forum for a week now and there seem to be some experienced, knowledgeable and helpful people around.

I want to do basic editing (effects, fades, titles, menus and music) and burn to standard dvd for my parents and then burn to standard dvd in HD format to play on a blu ray player. I also have the PS3 so thumb drive is another option. I am sure most of you recommend Vegas but are there any other options you would recommend (PD7, Premiere Element, Pinnacle) for someone just wanting to make good quality HD home video?

I read the long thread on i7 computers. It seems that some of you have bought the Dell Studio XPS with the 2.66 i7. How is that working for all of you? Would you buy it again? The price on these are good but the upgradeability seems very limited.

For you DIYers, can you give me your opinion? I have never upgraded or built a computer. I did add RAM one time if that counts for anything. I am pretty handy and able to do tinkering jobs. I have been looking at cyberpowerpc, ibuypower and cpusolutions at their customer builds and can get what I think is a good build for about $1700 w/out monitor. Main components are Gigabyte ud4 or Asus P6T MOBO, nvidia 9800 GT or 9800 GTX 1GB or ATI 4850 1GB video card, 64 gb solid state harddrive for OS and software, 500 GB HDD, 850W power supply, Asetek Liquid Cooling System (is this necessary?), 6GB (2x3) PC1333 Corsair Dominator RAM, Blu Ray player drive and 2nd drive for RW DVD, 12in1 media reader, Vista Home Premium 64bit. I also went to NewEgg and selected all the components I think I would need and it seems like for me, it would make more sense to order one and have it put together buy one of the 3 companies mentioned above. Your thoughts?

Thanks for any advice you will offer!