not sure what those ones are but...

antenna holder [link]http://www2.towerhobbies.com/cgi-bin/WTI0001P?&I=LXHMG3[/link]

there is the 180cc miss vegas tank you can use [link]http://www2.towerhobbies.com/cgi-bin/WTI0001P?&I=LXMNL3[/link]

or go with twin ofna 125cc for a huge 250cc [link]http://www.rcuniverse.com/forum/m_5419840/anchors_5764762/mpage_1/key_dual%252Ctank/anchor/tm.htm#5764762[/link]

tank here [link]http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXBM24&P=7[/link]

or there is a290cc fuel tank in this buggy
[link]http://www.ripmax.com/item.asp?itemid=C-XTM-XLB[/link]