If you've never used Tyranitar before, you could get Larvitar from Celadon game corner (8888 coins) and let him tour around Kanto with you. He starts at level 40 so he won't be too far behind the rest of your team. He has higher attack than Houndoom so it makes better use of Dark moves (and Earthquake/Rock Slide/Hyper Beam), but also has lower speed and special attack and no Fire STAB. He can use some Fire moves too, but won't make as good use of those as Houndoom would. Up to you.
Skarmory is so cool I would keep him even if he's a little on the weaker side. But a Dodrio can do a lot of damage with its high attack and STAB'd Drill Peck and Return.
>>34934299Jynx has good speed too. I've been using Lapras and without extra levels or a few Carbos she has some real trouble with Lance.