Get a cheap miniDV camcorder.. which ever brand
For Hi- 8 It would depend how much you wish to spend and how precious the footage is ( I have perhaps a few more than yourself

but I also have Digital 8 camcorder which digitises them internally for PC capture via firewire. Sony dont make those anymore: handy if you can get one though
I would suggest you ( to simplyfy things) record them via the camcorder 9 perhaps using S-video) to a setop DVD recorder, make DVD video discsk and copy these to you HDD
Settop DVD recorders arent overly expensive and are hassle free compared to using the PC method...
If you must use your PC directly, There are cheap ( and not cheerful devices) you can use to transfer to PC ( I saw a few in Maplins the other day)
Thankfully there are also There are " midrange" products ( Like the Dazzle seriess) Also available at Maplins/ PC world
and there are Very good
ADVC type kit ( I linked the very cheapest)