A close friend of mine bought after reading raving reviews of some new Kef bookshelfs (I really don't know which) a pair for 460 Euro new. A year later we had a Garden party and i had my PC2002M paired with some B&W DM110 playing music all the time. After this evening he took the DMs home for comparison. One day later he called me upset and told me, that he was shocked how much these UK girls sounded better than the Kefs. I was sceptic and drove over to him and yes, these 25 years old B&Ws where beating the new Kefs with ease. Now he is B&W owner. No matter I'm 80s B&W fan I really expected the Kefs being better but really no chance, they where not worth the money and we both wondered how they could get such sparkling reviews. I have to say that he is (I don't know the english term for this, one may help) a "master of musical instruments building" :headscrat and has good ears.
My advice would be to get the Dm220 and the DM4. The 220s will deliver rich and full sound with a smooth and deep bass extension, while the DM4 will be excellent and precise monitors but not as impressive for the first moment.
Note that monitors usually don't sound spectacular in any way, just clean and neutral, which is highly desirable and which grows on one once "learned". It's an addictive experience.
But when it comes to having loud and shaking beats you may take the 220s. Not to mention the DM220 (domestic monitors) beeing not precise, but they will have a kind of more overall pleasing sound, while the DM4s may show the weakness of your records.
My advice always will be to have both. If you have to choose and I see your preferred music, I would go with the 220s. While the DM4 are the higher league and hard to get for this price afaik, leastways here in Germany.
And as always at this point: the old B&Ws are ugly hungry for current. You need massive amps to make them sing. I believe your amps will not offer you a satisfying experience with B&Ws from this era. At least 150WPC (8Ω) for the DM220s. They will be thankful.
Let us know!
Best regards
Marne