a yaoi with a small uke and a big uke?

i mean big seme

http://www.mangago.zone/read-manga/bousou_kareshi/an/bousou-kareshi-chapter-4.html/4/

http://www.mangago.zone/read-manga/usagi_otoko_tora_otoko/

Sorry that wasn't what you asked for.

are you looking for shotacon? (personally, not my type, but....)
http://www.mangago.zone/read-manga/aishichattano/
http://www.mangago.zone/read-manga/crazy_for_daddy/
http://www.mangago.zone/read-manga/oucho_haru_no_yaoi_no_romance/
http://www.mangago.zone/read-manga/tsuki_ni_ookami/
or you could check out the shotacon category:
http://www.mangago.zone/genre/Shotacon/?f=1&o=1&e=

nanu-nana has a list tall seme x small uke:
http://www.mangago.zone/home/mangalist/43665/