I agree it's a good idea - we just bought 20 year term for ourselves this summer. We checked rates through our car/home insurance agent, through a broker via our financial adviser, and I did the SBLI get a quote page. (Disclaimer: I work for SBLI, but don't get a discount). Insurance through our car & home insurance agent was the most expensive, the range from the broker was interesting. I would normally go with the cheapest, but familiarity with the company made me go with SBLI - which surprisingly wasn't in the list from the broker.
What we didn't buy, but I'd consider, is Waiver of Premium coverage. During your 20 year term it's not cost effective, basically insurance on your insurance. At the end of the term you can continue the life insurance coverage at a hugely inflated rate. Healthy people don't do this - they get new underwriting and a new policy, if it's still needed. If you are disabled though, and have Waiver of Premium covering your premiums, suddenly you have free life insurance to age 85. It's still a long shot, so I didn't go for it, but our financial adviser was a proponent.
And good to know: the underwriting process feels like it takes forever. In the digital age I expected a determination in a few days. We had to wait over a month to hear if my husband's borderline high blood pressure was considered "controlled" so he'd get the Preferred Plus rating.