Hi Dave:
You could consider WorthIt Fixed Assets. It's a standalone product. It's moderately priced, in the $3,000 to $4,000 range. They sell through the dealer channel.
The only disadvantage is that it doesn't have an interface to Adagio. However you should be able to print a monthly G/L summary and manually input the figures into Adagio.
Ken Aberdeen was looking for something similar earlier this year. He probably can provide his experiences.
See the following link for details:
Product Details