Is an imac for me

Hi All,Hope you can help with what is at the moment a problem.
I have a pc over 10 yrs old so i need a new one and have been considering getting a mac.One of things i am looking to do is video editing,I have lots of old vhsc homemovies so hope to hook up to the mac via a video player.I also have loads of mini dv tapes which gain i would like to get on to dvd and also backed up.And now for my latest buy a panasonic tm900 which records in 1080p and uses a avchd file.My problem is this i understand imovie or final cut dosent edit adchd and the file needs to be converted my worry is it will loose quality ?.I took my camera into my local apple store and they couldnt get any 1080p avchd files from my camera to play on imov to see if there is any quality loss but they didnt have the software to convert the file.If i decided to go for adobe premier i understand this works with the avchd file but would the imac im looking at be man enough for the job to edit acvhd. 27-inch: 2.7GHz
2.7GHz Quad-Core Intel Core i5
2560 x 1440 resolution
4GB (two 2GB) memory
1TB hard drive1
AMD Radeon HD 6770M with 512MB
Basically i want to archive all the native avchd files on an external harddrive via the imac then import them for editing and then after completing the movie delite them from the mac and leave the original files on the ex hard drive.
Really need your help people thanks in advance
Lee

think ive posted this in the wrong section Sorry......perhaps one of the mods will move it to the video section.

Im not expert but i believe your CPU you described will carry the load. I think its safe to say that you would want to upgrade your ram to 8 or 12. I see people on here that have 12 just for everyday uses. I have 8 and am very happy with it (again, just for everyday use). Just check out the specs for the vid software you want to use. I have no knowledge of the file formats and what not, but I'm sure there is something out there of equal quality to FC that jives with your format.
Just wait it out a bit, and somebody will be on here to comment on your concerns.

Yes, an iMac would be a great choice.

Yes, you'll have to convert the AVCHD most likely (some programs will in some circumstances convert on the fly for you -- AVCHD is a format not a set of codecs so it can get tricky*), but no it doesn't have to introduce any quality loss. AVCHD was never designed as an editing format, which is precisely why Apple developed the (lossless) Apple Intermediate Codec.

*stupid camera manufacturers can't agree on a standard AVCHD set of codecs. Lame!