Gilles,
I recently installed a 750W converter and my instructions said the same
thing.  Went to Circuit City and they wanted a small fortune for the fuse
and fuse holder (a lot more than I paid for my inverter).  Ended up going to
a custom car stereo store and they said all I needed was a 60 or 70 amp fuse
and they fit in an inline holder.  I got the 80 (I think this was the
largest you can get with their inline holders and I'm more than covered
according to the guys at this shop).  Paid less than $10 for the entire set
up and haven't had any problems. You should be ok with an 80amp fuse if you
aren't continuously using a lot of power tools, etc.  Talk to someone at a
custom car stereo store and they should be able to tell you what you need
and also save you some $ on the fuse set up.  Good Luck - Chris

        >Re: Installing a 1000W converter
        >Hi,
        >I want to isntall a 1000W converter from my Optima yellow top.  In
the     >instructions they say to put a 150ADC fuse between the
converter an the        >battery.  I find this fuse to be very big.  Anyone
on the list did         that    >kind of installation?  If yes what size
fuse    did you use?
        >Best regards.
        >Gilles Turmel