With BatchPhoto you can create a single multi-page TIF image from multiple JPG images (or any other image format).
Here are the steps:
1. Add your source JPG images in Step 1
2. Optionally add the Resize filter in Step 2 to make all your images the same width
3. In Step 3 select TIF as the Output Format and check the box underneath (Create a single multi-page document).
You can try BatchPhoto for free from here: