SDS Drill and Core-cutter bits

I want to use a core-cutter to drill a hole for my new boiler's flue. Two questions:
1. HSS charge 30 quid to hire a heavy duty drill SDS for one day. I see Screwfix are selling cheapo versions (quote 94802) for the same price. Will this do for a 107mm core-cutter bit? Obviously, I would rather buy than hire, given the price is the same. But not if the cheapo won't do the biz.
2. HSS only hire out 100mm or 125mm core-cutters. I want 107mm. Where do I best hire/buy that? Or will 100mm do for a 100mm flue. (Vaillant Ecomax 828E - horizontal flue out the back - old victorian brick wall.) I am not keen on drilling the hole well over-size and then filling it.
Thanks
Geoff
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.