Vacuum Hub bolts

I have broken one of the E10 head bolts that hold on the vacuum hub cover. The torque wrench hadn't clicked and there was that wrong feeling you get just as a bolt shears. I am expecting a lot of fun extracting it as it broke almost flush with the surface.  I have bought left hand drill bits and stud extractors but putting the job off.
The bolts are about £7 - 8 each and it seems to make sense to replace the lot.  For about £27 I can buy 50 of these -  www.westfieldfasteners.co.uk/BO_ScrewBolt_Unbrako_SHCap_M8.html   - that way I can throw away a full set every time I take them out for less than the price of one Suzuki bolt.
My question is - will they be a suitable replacement?  Should I look for a regular Torx instead?

Thank you

Ray

I have often wondered why these bolts are so fancy on the Jimny, to my untrained eye they just hold a cover on. Any reason other than they are just tight to achieve a vacuum seal without a gasket?
I can't recall the bolt size, but if M8 as indicated by the link then 12.9 grade should be good to 40NM. Again I can't recall the torque figure required, but it's about or less than this they should be fine.
I Would try to get something with a better corrosion finish than the black passivate, they will rust up faster than the Jimny 

Just my opinion.
Mike

I have just found that the original bolt is described by DIN34800.  Can't find anyone selling them yet.  All of the socket head bolts seem to be self-colour, bzp or stainless.

According to a quick search they appear to be 8.8, but it also appears to be more about the head shape "small flange" rather than the strength. I would still be happy at 12.9.
www.fastenerdata.co.uk/fasteners/socket/...ade-88-din34800.html

www.spaldingfasteners.co.uk/m8-metric-12...el-socket-cap-bolts/

Sticking with M8 although I remember the being smaller, but it's been a while since I had them out.

Thank you, I was just looking at Spalding.  I am still learning about this - thought I had read that 12.9 is higher spec that 88 but the torque on these 48NM which seems a lot.  I will take one out tomorrow to check the size.  Need to find out whether it is a fine thread as well.