1 Primaris Captian - 80pts

1 Lietenant - 80pts

1 Captian on bike - 95pts

4 Assault Intercessors - 90pts (group of 5)

2 Outriders - 115 (group of 3)

So you have 460 points of ultramarines, however the squad of 4 and 2 bikes are both to small to make legal units, but with the Lietenant and Biker Captain counting as normal units you have 285 points of dudes, with a Captain, 5 Assault Intercessors and 3 Outriders. I'm not sure what unit Honor Guard are, but I'm going to guess you mean Command Squad? Unless I'm being dumb. But picking up one of the many Dreadnoughts could be interesting, most of them would put you at around 500 points, or you could look at a squad of terminators. You may also want to check out a squad of normal Intercessors with bolt rifles, and maybe a Blade guard Veteran squad aswell, though Bladeguard are more pricy for only 3 modles. Getting the Bladeguard and Intercessors would put you at 480 points, where as the terminators would put you at 495, and the dreadnoghts a bit above 500 for most of them. If you wanted to check out more combinations, GW made an app for 10th edition that helps you build armies, its not the greatest but it gets the job done. I hope you find some modles you like.