I showed a picture of Lily to my husband at lunch. It was the picture in the last catalog. He didn't like the bag, he thought it was too busy, and didn't care for it in black, but said maybe he'd like it beter in the whiskey color. I also showed him a pic of Gigi in the catalog, but it was the signature version and I explained to him I'd be getting Clay leather, he said he liked that bag better...(not that his opinion usually sways me...)
First, DH doesn't know what you want him to say, so don't put him on the spot.
Next, I own the Whiskey Mandy and the Lily in Whiskey & Atlantic. The Mandy & Lily are totally different bags, one's a shoulder bag the other is a satchel (with shoulder option). When I carry my Lily I generally leave the zipper open in the front with the tab closed. Then I can slip my hand in for something quickly, or by undoing the tab, I can remove something larger (wristlet, etc.).
Also, I own the Clay Gigi, which is gorgeous in her own right, but not to be compared to the Lily. I haven't seen the boots you want IRL, but they're probably very cute.
I vote that you get the Lily, because you obviously really, really want her, and the 25% is a huge savings. I think the Gigi will be available for a bit longer and these are also available at Nordstrom. They probably won't last until Nordstrom's Fall Sale, but you might reserve buying the Gigi in the next PCE.
I think if you justify buying more items with the funds you have available and miss out on the Lily, you'll be dissappointed down the road because you might constantly say, "I should have..."
Follow your heart and make the decision that you think will bring YOU the most happiness, Good Luck!