HI 69 Cooper
as said above holden grey are .875 and when shortened a little work well. I have been told by reputable people that hillman hunter and MGb pushrods will also work BUT not sure of availability /models etc and also the mgB ones are .90 and so are pushing the limit in terms of lifter bore ( so much so that sleeves may be prudent ..due to casting variations etc .. you just might push through... machine costs to widen/straighten/ line up the lifter bores is also requiring expertise and is probably achieved easier with a Cooper S block with the tappet covers...
if you are into new, then go to BWR performance/racing or similar ( Brain waters racing oregan (sorry just found link)
http://www.bwrperformance.com/a-series-all.html) who has had new and correct and expensive lifters done but atm no stock on the standard large diameter ones, but i think he does have DLC ones..... i think these versions will all be very good
I am running holden greys in an old school Group nb car because they were there, i do like them but i also think it is an expensive way to go and i am not sure it is warranted with our newer camshaft profiles... it took me quite some time to find a second set ( well actually a set and a half for the mini) as the old holden guys are doing exactly that HOLDEN on to them
talk to your camshaft designer/grinder to get their thoughts