First off, the image sequence will be either TGA or JPG, not both. 🙂
If your sequence is a bunch of individual TGA or JPG files:
1. Open Quicktime and go to File --> Open Image Sequence.
2. Open the first file in the sequence. An "Image Sequence Setting" window with a pulldown menu will appear.
3. Choose the frame rate that matches your FCP sequence and click "OK." Quicktime will then load the group of images as a sequence.
4. Go to File --> Save and make sure that the "Self-contained movie" option is checked. Now, click "Save."
Quicktime will then wrap the image sequence as an .mov that you can bring into FCP. Keep in mind that more often than not, you'll have to render the sequence on your timeline for it to play back at full frame rate.
Hope that helps.