2 lifters are bad...which stock replacements do I need to order?

Hey guys,

The lifters in cyl. #1 and #8 are bad.

They are stock lifters.

Do I need to order a whole set or can I just replace the bad ones?

Also which ones are the stock replacements?

Summit only seems to carry aftermarket.
I found these sealed power hydr. lifters...but is it ok to mix these with sotock lifters?
http://store.summitracing.com/partd...908282+4294924653+4294840044+115&autoview=sku

Will these work as replacements?
http://www.discountautoparts.com/Re...Lifters and Timing&clientid=discountautoparts

Thanks.

I appreciate it!
Patrick

BTW.The car is a 2001 GT.

bump